Lighting an environment through a light valve

ABSTRACT

A system may include a light valve exposed to incident light from an external light source. The light valve may independently modulate multiple wavelength bands of the incident light that are transmitted through the light valve and into an environment that the system illuminates. A control system can operate the light valve to control a spectral distribution of light transmitted through the light valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent document is a continuation and claims benefit of the earlierfiling date of U.S. patent application Ser. No. 14/299,317, filed Jun.9, 2014, which is hereby incorporated by reference in its entirety.

BACKGROUND

Light from the sun may be the least expensive and most available daytimelight source for lighting and most buildings have windows that passsunlight or light from an exterior environment into the interior of thebuilding. Curtains, blinds, and other window shades are commonly used toregulate the amount of sunlight that enters an environment. However, thecapabilities of current windows and window controls are limited.

SUMMARY

In accordance with an aspect of the invention, a lighting system canemploy an electronic light valve or other electrically controllabledevice in a window or other light passage to receive external light suchas natural sunlight and modulate the received light to control spatial,directional, angular, temporal, or spectral variation of the lighting ofan environment. In one specific configuration, the light valve mayinclude a panel having a structure similar to structures found in liquidcrystal display (LCD) or reflective display technology. The light valvemay particularly be deployed as, on, or adjacent to a window, askylight, or other passage that passes light from one environment intoanother, e.g., from an exterior environment to an interior environmentor other at least partially sheltered environment. The light valve mayoperate in conjunction with a control system such as a general purposecomputer or dedicated hardware that interprets light control informationto control the spatial, temporal, and spectral characteristics of lighttransmitted through the light valve. The control information may takethe form of lumen scripts that may be stored locally or streamed to thecontrol system or the light valve.

One specific implementation is a system for illuminating an environment.The system includes a light valve to independently modulate transmissionof several wavelength bands from a light source such as the sun, throughthe light valve and into the environment that the system illuminates.The control system may operate the light valve to control a spectraldistribution of light transmitted through the light valve and thereby tocontrol the illumination of the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an implementation of a system using an external lightsource to light an interior environment.

FIG. 2 shows an implementation of a light valve system.

FIG. 3 schematically illustrates a light valve in accordance with animplementation using stacked, spectral filters.

FIG. 4 schematically illustrates a light valve in accordance with animplementation using laterally-distributed, spectral filters.

FIGS. 5A and 5B show implementations of luminaires employing a manmadelight source and a light valve to alter the spectral, temporal, angular,or spatial distributions of the illumination of an environment.

The drawings illustrate examples for the purpose of explanation and arenot of the invention itself. Use of the same reference symbols indifferent figures indicates similar or identical items.

DETAILED DESCRIPTION

A lighting system can employ an external light source such as the sunand provide an interior or sheltered environment with lighting orillumination having spatial, angular, temporal, or spectral variationscontrolled according to illumination data sometimes referred to hereinas a script. FIG. 1 shows an example of a system 100 providing lightingor illumination to interior environments 112 and 116, which may berooms, compartments, or other spaces inside a building 110. Interiorenvironment 112 may include a building portion that receives lightdirectly from the outside of building 110, e.g., a room with windows,doors, or skylights, and interior environment 116 may include a buildingportion that indirectly receives exterior light through an interveningcompartment of building 110. Building 110 may be, for example, a home,store, office building, healthcare facility, hospital, warehouse, or anyother building. Environments 112 and 116 may, for example, be aninterior space such as a room, an attic, a basement, the whole of theinterior of building 110, or any compartment separated, for example, bywalls, ceilings, or floors of building 110.

The environment outside of building 110 includes one or more externallight sources 120. In examples described herein, external light source120 is daylight which may include: sunlight directly from the sun;sunlight scattered by air, e.g., blue sky; scattered by othermeteorological phenomena, e.g., by clouds; or scattered or reflected byother natural or manmade objects, e.g., from the moon, mountains, andbodies of water. The sun produces light having a broad spectrum and ahigh intensity on most days, but incident light 122A, 122B, 122C, and122D, generically referred to herein as light 122, varies depending onfactors such as the time of day and conditions in the exteriorenvironment. In particular, light 122 may include sunlight, which oftenincludes bright, nearly collimated light from the direction of the sunand diffuse light from other directions in the sky. Further, sunlightmay be scattered, reflected, or filtered by meteorological conditionssuch as clouds, by natural features such as snow covered or forestedmountains, bodies of water, or other terrain, or by manmade featuressuch as neighboring buildings or other structures. FIG. 1 illustrates anexample including a light collection system 128, e.g., mirrors on asun-tracking mount, that reflect or otherwise collect sunlight toincrease the amount of incident light 122 available for interiorlighting. Accordingly, the direction, the angular distribution ofculmination, and spatial distribution of incident light 122 may vary.The spectral composition of incident light 122 may also vary. Forexample, daylight generally varies with direction and time. Inparticular, diffuse daylight often has a higher color temperature thandoes direct sunlight.

Daylight is free and a high quality illumination source of incidentlight 122, and the sun is described herein as a primary example of anexternal light source 120 that may provide interior lighting. However,other external light sources 120 such as the moon, stars, or manmadelight sources that happen to be in the exterior environment mightalternatively be available or may contribute to incident light 122A,122B, 122C, and 122D.

Building 110 includes one or more active light passages 130 such aswindows, doors, skylights, or other light passages that pass light 122from external sources 120 into interior environment 112. In the exampleof FIG. 1, embodiment building 110 includes a window 130A and a skylight130B on the sunny side of building 110 and a window 130C and a skylight130D on a shady side of building 110. Windows 130A and 130C andskylights 130B and 130D may occupy large areas, e.g., widths or heightson the order of tens of centimeters to one or more meters. Window 130Aand skylight 130B may face south in the northern hemisphere (or north inthe southern hemisphere) to receive intense and significantly collimateddaylight during most of the day, or may face east in the morning or westin the evening. Window 130C and skylight 130D may face north in thenorthern hemisphere (or south in the southern hemisphere) to receivediffuse light during most of the day or may face east or west in theevening or morning.

Windows 130A and 130C and skylights 130B and 130D may includeconventional structures such as frames and glass panes, but one or moreof light passages 130A to 130D may additionally or alternatively includerespective light valves 132A to 132D that are capable of modulatingmultiple spectral components of incident light 122A to 122D reachinglight passages 130A to 130D from external sources 120. In oneconfiguration, each of light valves 132A to 132D fits into openingsadjacent to conventional windows, skylights, or other light passages. Inanother configuration, one or more of light valves 132A to 132D mayreplace a traditional transparent, diffuse, or translucent structuresuch as glass or plastic panes in respective light passages. Asmentioned, each of light valves 132A to 132D may employ color orspectral filtering technology such as employed in LCD or reflectivedisplays, but each of light valves 132A to 132D may be able to modulatemore spectral bands than display systems generally accommodate. Also,light valves 132A to 132D may not require the spatial or “pixel”resolution normally required for video displays because light valves132A to 132D are primarily intended for illumination and not fordisplaying an image for viewing. Although, in some cases, a light valve132A, 132B, 132C, or 132D may both provide illumination for an interiorenvironment and have a viewable image on the light valve. Whendisplaying an image is not required, a light valve may uniformlymodulate the spectral content of transmitted or reflected light acrossthe entire area of a window or skylight. Alternatively, a light valvemay contain an array of independent modulation areas, and each area mayhave dimensions typical of current displays or may have larger pixelswith dimensions on the order of millimeters to meters. An array ofindependent modulation areas may be particularly desirable for creatingspatial variations in lighting, for example, to create a bright lightsource or sources that move in the illuminated environment in a mannersimilar to movement of the sun, the moon, or stars. Similarly, a lightvalve with an array of independent modulation areas can create theeffect that clouds or other variable phenomena might have on lighting inthe illuminated environment and could simultaneously create an image ofthe clouds or other phenomena on the surface of the light valve.

Each light passage 130 in the illustrated implementation further hasvalve control electronics 134, which are shown in more detail in FIG. 2.In general, the light valve 132 of a light passage 130 is physicallylocated within the light passage, e.g., in the window, skylight, orother opening through a building barrier, and a frame or otherappropriate mounting structure 250 can hold light valve 132 in place.Valve control electronics 134 is not required to be in the opening oflight passage 130, so that all or portions of valve control logic 134may be remote from the opening. Valve control electronics 134 may belocal in the sense that it controls a single light passage location, butvalve control electronics 134 may work co-operatively with other controlsystems. In the implementation of FIG. 2, valve control electronics 134includes a communication interface 210 capable of communicating withsimilar communication interfaces in the valve control electronics of oneor more light passages 130 or with a main control system 140. Forexample, communication interface 210 may communicate with main controlsystem 140 or with other light valve systems through a network such as awireless (e.g., Bluetooth, Zigbee, or Wi-Fi) or hardwired (e.g.,Ethernet) network. Control logic 220, which may include amicrocontroller and memory storing control programs or scripts, mayemploy communication interface 210 to implement the suitablecommunications protocols.

During operation of system 100 of FIG. 1, each light valve 132 mayreceive incident light 122 and independently modulate or filter multiplespectral bands in multiple areas to produce transmitted light 114 thatis at least part of the illumination of interior environment 112.Control logic 220 operates drivers 230 of an active light passage 130,for example, to apply respective bias voltages to an array of regionsand to thereby control the transmission percentages for light indifferent wavelength bands passing through areas of the associated lightvalve 132. Such control is generally subject to programming, but controllogic 220 may also be able to access one or more sensors 240 and operatedriver circuits 230 based on sensor measurements in order to control thelight transmission characteristics of multiple independentlycontrollable areas of the corresponding light valve 132.

In the illustrated implementation, control electronics 134 includes oneor more sensors 240. Sensors 240 may be of any type including lightsensors, temperature sensors, motion sensors, occupancy sensors, orsensors of other atmospheric components or other conditions ofenvironment 112. Light sensors, in particular, may be capable ofmeasuring one or more characteristics of incident light 122 and/or oneor more characteristics of transmitted light 114. Some lightcharacteristics that could be measured include the intensity, direction,collimation, and spectral distribution of incident light 122 ortransmitted light 114. Control logic 220 may use such light measurementsor may send measurement data to main control system 140, for example, tobe used in a learning program or in coordinating operation of lightvalve 132 with operation of other light sources illuminating anenvironment. For example, control logic 220 or main control system 140may collect and process data from sensors 240 to learn thecharacteristics of a particular light valve 132 or of incident light 122at the light valve 132, and a learning program may then automaticallyadapt the operating parameters of light valve 132 to provide desiredperformance of an active light passage 130. Control logic 134 or maincontrol system 140 may also change lighting in environment 112 based onother types of measurements. If sensors 240 (or sensors 148) includeoccupancy or motion sensors, control logic 220 or main control system140 may modify the intensity or spectrum of light transmitted throughlight passage 130 according to the number or location of people inenvironment 112. If sensors 240 (or sensors 148) include chemical orenvironmental condition sensors, control logic 220 modify the intensityor spectrum of light transmitted through light passage 130 to provide awarning or notification of a sensed condition. Sensors 240 may also beused in predictive programming of light, for example, to anticipate thelight needs or desires of users based on sensed activity of the users.

In the system of claim 1, operation of light valves 132A to 132D may becoordinated through main control system 140. Alternatively, some, all,or none of light passages 130A to 130D may operate autonomously tocontrol the characteristics of transmitted light 114A to 114D accordingto the specific programming of that light passage 130. In oneimplementation, each of light passages 130A to 130D may filter incidentlight 122A to 122D so that its transmitted light 114A to 114D has aspectral distribution set or programmed for that light passage. Forexample, one or more of light passages 130A to 130D may be programmed tocompensate for a cloudy day by transmitting a higher percentage ofincident red light so that the corresponding internal lighting 114A to114D has a spectral distribution of a sunny day. More generally, valvecontrol system 134A to 134D or main control system 140 may be operableto select a script from among a library of scripts that describedifferent illumination schemes and according to the script selected, tocontrol respective transmission percentages for the wavelength bandsthrough the light valves 132A to 132D.

Illumination of interior environment 112 may include just transmittedlight 114A to 114D from light passages 130A to 130D or may additionallyinclude light from additional light sources 150. Additional lightsources 150 may be light sources that are not operating cooperativelywith light passages 130A to 130D. For example, light sources 150 may beconventional light fixtures or conventional light passages not having alight valve or other spectral control system or may otherwise beindependent of or not in communication with main control system 140 orlight passages 130A to 130D. Alternatively, additional light sources 150may include one or more luminaires that operate cooperatively with lightpassages 130A to 130D and may produce light with spectral distributionsunder control of main control system 140. For example, additional lightsources 150 may include a luminaire such as described in U.S. Pat. No.8,021,021, entitled “Authoring, Recording and Replication of Lighting”or U.S. Pat. App. Pub. No. 2012/022904, entitled “Luminaire System,”both of which are hereby incorporated by reference herein in theirentireties.

Main control system 140 may be a computer system or a light player suchas described in U.S. Pat. No. 8,021,021 and may be able to processillumination data or scripts as described in U.S. Pat. App. Pub. No.2012/0229048. Main control system 140 may particularly be a computer ordata processing system including data storage or memory containingprogram code and lighting data or scripts 142, a processor capable ofexecuting the program code to implement an interpreter 144, a userinterface (not shown), and a network interface 146. In general, lightingdata such as scripts 142 may be purchased separately from control system140 and downloaded to storage in control system 140 or alternatively maybe streamed to control system 140 or light passages 130 as needed foron-the-fly control of lighting. Main control system 140 may furtherinclude a sensor system 148 that may be any type of sensor includinglight sensors, temperature sensors, motion sensors, occupancy sensors,or sensors of other atmospheric components or other conditions ofenvironment 112. A light sensor, for example, may measure the spectralcontent or other characteristics of internal light 114 or external light122 at one or more locations in interior environment 112 or outside ofbuilding 110. However, main control system 140 could employ measurementsof any type in control process such as described above, for example, tochange lighting in environment 112 adapt to lighting conditions,according to the number of users present in environment 112, to givewarning or notification of conditions in environment 112, or to predictthe light needs or desires of users based on the activity of the users.As already mentioned, main control system 140 may not be necessary, andlight passages 130A to 130D and light sources 150 may be able tocommunicate and cooperate with each other, e.g., through peer-to-peernetwork, without need of main control system 140.

System 100 may generally operate to allow a user to select a script 142from among multiple scripts 142, e.g., a library of scripts, that mayhave been installed in memory of main control system 140 or controlelectronics 134A, 134B, 134C, or 134D, e.g., during manufacture or as aresult of a subsequent user acquisition, e.g., purchases, downloads, orstreams. The selected script 142 may represent a lighting scheme thatthe user desires for interior environment 112. For example, a user mayselect a script 112 that provides spatial, directional, angular,temporal, and spectral variations in illumination of environment 112that: the user finds soothing, invigorating, or is otherwise intended toaffect the user's mood or performance; provides lighting thought to behealthy or medically therapeutic; displays the contents of environment112 in an aesthetically appealing, appalling or other chosen manner;displays or highlights items for retail sales; facilitates an activityundertaken in environment 112; or is coordinated with a multimedia orother presentation or performance occurring in environment 112. Maincontrol system 140 interprets the selected script 112 and may sendlighting data or instructions to the light passages 130A to 130D and anyluminaires among light sources 150 in communication with main controlsystem 140. In the control process, main control system 140 (or othercontrol system) may take into account sensor measurements ofillumination in environment 112 as described in U.S. Pat. App. Pub. No.2013/0307419, entitled “Lighting System with Sensor Feedback,” which ishereby incorporated by reference in its entirety. Main control system140 may also take into account measurements of the spectral distributionof incident light 122 from the external light sources 120.Alternatively, control may be independent of sensor measurements evenwhen such measurements are available.

Light valves 132A, 132B, 132C, and 132D alter respective incident light122A, 122B, 122C, and 122D to produce transmitted light 114A, 114B,114C, and 114D, and the alterations may differ and be coordinated bymain control system 140 or a peer system of control electronics 134A,134B, 134C, and 134D. In particular, transmitted light 114A, 114B, 114C,and 114D may have different spectral distributions selected according tothe selected script 142 for lighting of environment 112. Somecharacteristics of the illumination of environment 112 that a user maycontrol include current spectral, spatial, angular, or directionaldistributions of the illumination and evolution of time variations ofspectral, spatial, angular, or directional distributions ofillumination. For example, incident light 122A and 122B may have astrong directional or collimated component, which allows control ofcollimated components of the illumination of environment 112 accordingto a desired directional or angular distribution for lighting.Similarly, incident light 122C and 122D may be more diffuse allowingcontrol of diffuse components of the illumination of environment 112.

FIG. 1 shows main control system 140 as a separate and centralizeddevice, but the functions of main control system 140 may be included inor distributed among one or more other devices including but not limitedto light passages 130A to 130D or their control electronics 134A to134D.

Control methods and systems of illumination of an environment such asenvironment 112 that receives direct lighting from external sources 120through light valves 132A to 132D can also be applied to an environmentsuch as environment 116 that receives indirect lighting. In particular,environment 116 may receive light through a light passage 160 fromenvironment 112. In effect, environment 112 may mix light from lightvalves 132A to 132D and other sources 150 and a portion of that lightmay pass through light passage 140 to indirectly light environment 116.Light passage 160 in general may be a passive structure that permits thepassage of light through a building barrier such as a wall, floor, orceiling, or light passage 160 may include a light valve thatcontrollably filters spectral components of light. For example, lightpassage 160 could be substantially identical to light passages 130A to130D. In one configuration, light passage 160 (or light passages 130A to130D) could occupy the entirety of a building barrier such as a wall,ceiling, floor, or roof section.

Light valves 132A to 132D under control of valve control electronics134A to 134D or main control system 140 can independently modulatemultiple wavelength or frequency bands of the broad spectrum incidentlight 122A to 122D. For example, a light valve 132 may controltransmissive, reflective, or transflective effects that one or moremodulation areas have on specific wavelength bands of light. A lightvalve structure capable of such modulation can be based on modificationof display technology currently employed in computer monitors, flatpanel television, and e-readers. For example, layers from commonlyavailable LCD panels with standard red-green-blue (RGB) filters could beused as a light valve. A deconstructed computer monitor can provide anLCD matrix able to implement the basic principles of a light valvedescribed above, but the maximum intensity with a “white” screen may beabout 50% or less of the incident intensity. Also, when unpowered or“all black,” such a matrix may leak about 10% of the incident intensity.Technologies and structures used in reflective displays may providehigher maximum intensity or less undesired leakage. However,conventional display technologies may provide only three modulatedwavelength bands, e.g., red, blue, and green or cyan, magenta, andyellow. A higher number of filters, e.g., four, five or more, may bedesired to provide finer control of spectral distributions. A lowerspatial resolution light valve, e.g., with larger pixels or only asingle pixel, may be well suited to broad spectrum, high qualityillumination.

FIG. 3 shows a cross-section that schematically illustrates one exampleof a light valve 300, which may be used for light valves of FIG. 1.Light valve 300 includes N, where N is three or more and preferably fiveor more, selectively transmissive layers 310-1 to 310-N, genericallyreferred to herein as layers 310. Each layer 310 may be activated totransmit a controllable fraction of the incident light 330 in acorresponding wavelength band. Each layer 310 may transmit all or mostlight in the wavelength bands corresponding to other layers 310. Suchlayers 310 may be constructed using a variety of technologies that arein current use in displays or may employ techniques that are yet to bedeveloped. In one example, layer 310-1 to 310-N contain a liquid crystalmaterial to which different dyes are bound and electric potentials areapplied across layers 310-1 to 310-N to control how effective the dye isat absorbing or reflecting light in a wavelength band associated withthe dye.

In the example of FIG. 3, each of layers 310-1 to 310-N has an array ofupper electrodes 312-1 to 312-N and an array of lower electrodes 314-1to 314-N made of a transparent conductor such as indium tin oxide (ITO),and voltages between upper and lower electrodes may activate or changethe percentages of incident light that each layer 310-1 to 310-N absorbsor reflects from the respective wave length bands. Upper plates 312-1 to312-N or lower plates 314-1 to 314-N may be divided into areas thatdefine independent modulation areas or what might be referred to aspixels in display technology. However, a single “pixel” area coveringthe entire area of light valve 300 may be sufficient, or multipleseparate “pixel” areas may be large or may be controlled at the samepotential if uniform behavior is desired across the area of the lightvalve 300. If desired, a multi-pixel light valve 300 may create spatialvariation in the transmitted light. Driver circuitry 320 is electricallyconnected to the electrodes 312-1 to 312-N and 314-1 to 314-N and maycorrespond to all or a portion of valve control electronics 134A or 134Bof FIG. 1. By separate modulation of the wavelength bands correspondingto layers 310-1 to 310-N, light valve 300 can pass transmitted light 340having a different spectral distribution from incident light 330.

A light valve may alternatively employ laterally distributed modulationareas or sub-pixels that transmit different wavelength bands. FIG. 4,for example, shows a portion of a light valve 400 including one or morepixels 410, each containing M laterally spaced modulation areas 412-1 to412-M, generically referred to herein as modulation areas 412. The Mmodulation areas 412-1 to 412-M in each pixel 410 may include N (N≦M)different types of filters that modulate the intensity of light in Ndifferent spectral bands. For example, in a configuration in which eachpixel 410 contains nine modulation areas 412 corresponding to ninedifferent wavelength bands, each pixel may be able to independentlycontrol the relative intensities of up to nine different wavelengthbands. In one implementation, each modulation area 412-1 to 412-Mtransmits a controllable fraction of incident light having a wavelengthwithin a wavelength band corresponding to the modulation area 412-1 to412-M and absorbs or reflects light having wavelengths outside thewavelength band corresponding to the modulation area 412-1 to 412-M.FIG. 4 shows an example in which modulation areas 412-1 to 412-Mincludes respective active layers 413-1 to 413-M, generically referredto herein as active layers 413. Active areas 413-1 to 413-M overlierespective filter areas, 414-1 to 414-M, which may differ chemically,e.g., contain different dyes. In one configuration, each of modulationareas 413-1 to 413-M transmits a percentage of the incident light, andeach of the associated filters 414-1 to 414-M only transmits light in awavelength band corresponding to the associated modulation areas 412-1to 412-M. The percentages that modulation areas 412-1 to 415-M transmitdepend on respective voltages applied to respective transparent,terminal pairs 415-1 to 415-M, generically referred to herein asterminal pairs 415. Driver circuits 420 may be connected to pixels 410or modulation areas 412 to control voltages applied across electrodepairs 415 and thereby control transmission percentages of modulationareas 412 of light valve 400.

The examples of structures of light valves 300 and 400 illustrated inFIGS. 3 and 4 may be altered or combined in many ways. For example, twoindependent or cooperative light valves could be stacked or provided onopposite sides of a pane of glass or other intervening transparentlayer. The light valve structures described may also be combined withother optical elements or controls for other characteristics of thetransmitted light. For example, spectral filtering may be combined withoverall intensity control device such as an eletrochromic device.Optical elements could control coherence or diffusion of the light oruse an interference to change spatial distribution of the transmittedlight. The polarization or direction of the transmitted light could besimilarly controlled.

A multi-channel light valve such as shown in FIG. 3 or 4 can be usedwith broadband light sources other than the sun and particularly withmanmade light sources to create a luminaire with a controllableillumination spectrum and without the need of an external light source.FIG. 5A, for example, illustrates a luminaire 500A including a lightvalve 132 that filters incident light 512 from a light source 510 toproduce a programmable spectral distribution for illumination 514 of anenvironment. Light source 510 is a manmade, broadband light source andmay contain one or more High-Intensity Discharge (HID) lamps, halogenlamps, LEDs, lasers, collimated light sources, or polarized lightsources. A valve control system 134, which may be substantially the sameas described above with reference to FIGS. 2 and 3, can be used tocontrol the respective transmission percentages that occur for Nwavelength bands where N is three, four, five, or more. Luminaire 500may then be used in substantially the same manner as luminairescontaining multiple distinct types of light sources such as described inU.S. Pat. No. 8,021,021 or U.S. Pat. App. Pub. No. 2012/0229048.

Luminaire system 500A has its own light source 510 and does not need tobe mounted in a light passage. Accordingly, a mounting system 550 may beemployed to mount or set luminaire 500A anywhere. Luminaire 500B asshown in FIG. 5B uses a frame or mounting system 250 that permitsmounting of luminaire 500B in a light passage such as a window, door, orskylight as described above. In such configurations, light source 510may be retractable, transparent, or have openings that pass sufficientexternal light 122 that light valve 132 can be used to modulate thecharacteristics of incident daylight 122 (with or without a contributionfrom light source 510) for internal use as described above withreference to FIG. 1. When the external light may be insufficient, e.g.,at night, light source 510 in luminaire 500B may be activated, so thatlight source 510 alone or with an available external light sourceprovides light incident on light valve 132. For example, luminaire 500B,when employed in a light passage, may transition between solelytransforming incident daylight 122 according to a lighting scheme chosenfor illumination 514 of an environment and powering up light source 510to provide incident light 512 as needed to maintain the lighting schemechosen for illumination 514 of the environment.

Some elements of the above-described systems can be implemented in acomputer-readable media, e.g., a non-transient media, such as an opticalor magnetic disk, a memory card, or other solid state storage containinginstructions that a computing device can execute to perform specificprocesses that are described herein. Such media may further be or becontained in a server or other device connected to a network such as theInternet that provides for the downloading or streaming of data andexecutable instructions.

Although particular implementations have been disclosed, theseimplementations are only examples and should not be taken aslimitations. Various adaptations and combinations of features of theimplementations disclosed are within the scope of the following claims.

What is claimed is:
 1. A lighting system comprising: a light valveconfigured to receive incident light on a first side of the light valve,the first side being outside an environment to be illuminated, the lightvalve independently filtering a plurality of wavelength bands of theincident light to produce from a second side of the light valveillumination of the environment.
 2. The system of claim 1, wherein thelight valve independently filters at least five different wavelengthbands.
 3. The system of claim 1, wherein the light valve is furtherpositioned to receive at least a portion of the incident light from anatural light source.
 4. The system of claim 3, wherein the naturallight source is the sun.
 5. The system of claim 1, further comprising amounting structure to mount the light valve in a light passage through abarrier that is part of a building containing the environment, theincident light being from a second environment on a side of the barrieropposite from the environment.
 6. The system of claim 5, wherein theenvironment to be illuminated comprises an interior space in thebuilding, and the barrier is one of a wall, a ceiling, and a floor ofthe interior space.
 7. The system of claim 6, wherein the secondenvironment is an exterior space outside the building containing theenvironment to be illuminated.
 8. The system of claim 5, wherein: theenvironment to be illuminated comprises a first room in the building;and the second environment comprises a second room in the building. 9.The system of claim 1, further comprising a broadband source configuredto provide at least a portion of the incident light.
 10. The system ofclaim 9, wherein the broadband source includes one or more light sourcesselected from a group consisting of a High-Intensity Discharge (HID)lamp, a halogen lamp, a laser, a source of collimated light, and asource of polarized light.
 11. The lighting system in claim 1, furthercomprising: a control system connected to operate the light valve tocontrol a spectral distribution of the illumination.
 12. The system ofclaim 11, wherein the control system is operable to select a script fromamong a plurality of scripts that describe different illuminationschemes and to control respective modulations of the wavelength bands inaccordance with the script selected.
 13. The system of claim 11, whereinthe control system comprises a communication interface to communicatewith one or more lighting elements that cooperate with the system toilluminate the environment.
 14. The system of claim 11, furthercomprising a sensor selected from a group consisting of a temperaturesensor, a motion sensor, an occupancy sensor, a chemical sensor, and anenvironmental condition sensor.
 15. The system of claim 11, furthercomprising a sensor, wherein the control system selects operatingparameters of the light valve based on measurements from the sensor. 16.The system of claim 15, wherein the sensor measures spectral content ofthe illumination.
 17. The system of claim 15, wherein the sensormeasures one or more characteristics of the incident light.
 18. Thesystem of claim 15, further comprising a learning system executed by thecontrol system, wherein the learning system processes data from thesensor and adapts the operating parameters of the light valve based on acharacteristic learned from the data.
 19. The system of claim 15,wherein the control system modifies intensity or spectrum of theillumination transmitted through the light valve to warn of a sensedcondition.
 20. The system of claim 15, wherein the control systemmodifies the illumination based on sensed activity of one or more usersin the environment.